Magnetic head and magnetic recording/reproducing system

Abstract

A high output, magnetoresistive head with a CPP structure is disclosed which reduces or prevents deformation near the air bearing surface of the read element portion layer at the time of air bearing surface processing. In the CPP structure magnetoresistive head, the deformation near the air bearing surface as a result of mechanical polishing during the air bearing surface processing can be reduced by forming deformation prevention layers having a higher shear modulus than the first ferromagnetic layer, and a second ferromagnetic layer between a magnetoresistive film and at least one of a lower shield layer and an upper shield layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a Continuation of U.S. App. Ser. No. 10 / 369,682 filed on Feb. 21, 2003, and claims priority from U.S. App. Ser. No. 10 / 369,682 filed on Feb. 21, 2003, which claims priority from Japanese Patent Application Nos. 2002-252348 and 2003-001669, filed on Aug. 30, 2002 and Jan. 3, 2003, respectively, the entire disclosures of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a magnetic head having a CPP (Current Perpendicular to the Plane) structure in which a sensing current is applied in a direction substantially perpendicular to the interface between the first ferromagnetic layer and the intermediate layer of a magnetoresistive film and the interface between the intermediate layer and the second ferromagnetic layer of the film and to a magnetic recording / reproducing system having the magnetic head. [0004] 2. Description of the Re...

AI Technical Summary

Benefits of technology

"The present invention provides a magnetoresistive head with a CPP structure that has a high yield and is less damaged by mechanical polishing. The head has a deformation prevention layer that prevents deformation during processing and has a high output when air bearing surface processing is carried out. The invention also provides a magnetic recording / reproducing system with high linear and areal recording density that incorporates the magnetoresistive head. The technical effects of the invention are improved performance and reliability of the magnetoresistive head for high-density magnetic recording applications."

Problems solved by technology

To achieve a narrower shield to shield distance, in the case of a so-called CIP (Current Into the Plane) GMR film in which a sensing current is applied to the plane of a magnetoresistive film, as the thickness of an insulating gap layer interposed between shield layers and the GMR film and between shield layers and electrode films for supplying a sensing current to the GMR film become small and a sensing current leaks out into the shield layer, when the shield to shield distance is set to about 80 nm or less, the yield greatly lowers, and it is technically difficult to reduce the shield to shield distance to 70 nm or less.

Since the CPP structure is a new structure unlike the CIP structure whose technology is becoming mature, it still has some problems to be solved.

One of the problems is a air bearing surface processing technology.

However, the step of obtaining a desired sensor height using the plasma process disclosed by JP-A 11-175927 in air bearing surface processing has a poor throughput, is not practical and needs mechanical polishing.

Therefore, the main cause of deteriorating properties during air bearing surface processing is the shield layer.

More specifically, when a air bearing surface is to be polished, a metal constituting the shield layer is dragged from the insulating gap film to the GMR film, thereby causing a phenomenon that a sensing current leaks out from the GMR film into the shield layer to greatly reduce output.

However, as the magnetoresistive film, the gap layer and the shield layer are made from a metal in the CPP structure head, all of them are readily deformed, whereby the dragging of a metal constituting the shield layer which occurs in the CIP structure head occurs, and also the deterioration of characteristics is caused by the deformation of the gap layer and the deformation of the magnetoresistive film (disorder and fault of the laminate structure).

Therefore, in the case of the CPP structure head, taking the mechanical properties of only the shield layer into consideration is unsatisfactory, and it is important that the magnetoresistive film, the gap layer and the shield layer should be entirely made difficult to be deformed.

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